The firm is responsible for a number of familiar brands including Lynx toiletries, Comfort fabric softener and Dove soap, and Mr Polman indicated that jobs could be at risk if the UK left.

He told Channel 4 News i t was "ludicrous to think you can be alone in the UK and give up belonging to one of the most prosperous and biggest trading blocs".

Highlighting Wall's Magnum ice cream, Mr Polman warned about trade restrictions " because undoubtedly if the UK were to Leave, the conditions will not be as good as if they stay in".

He said: "For example, you would have import duties on dairy, anybody from outside the EU has import duties that could be up to 40%, 50% so the price of dairy products will go up, the price of ice cream will go up. And ultimately, the consumer will pay the price for that."

Mr Polman added that the impact of Brexit on the UK economy "will undoubtedly put jobs at risk in this part of the world".